1. Field of Invention
The present invention relates to broadcast systems and in particular to broadcast systems in which a user designates particular information to be received.
2. Related Art
There is a growing demand for systems that deliver information and entertainment that is tailored to an individual user""s (system subscriber) preferences. Current information and entertainment delivery systems servicing many end system users (e.g., xe2x80x9cThe Internetxe2x80x9d having an origin in the network of interconnected networks developed under the Advanced Research Projects Agency) offer a variety of information services. End systems (e.g., personal computer) are typically at fixed locations and are physically connected (wired) to the information delivery system.
Wireless (e.g., radio) systems have been implemented to allow users access to information while mobile. Two-way high-speed network connections have been implemented in wide bandwidth wireless communications systems (e.g., Wide band Code Division Multiple Access (W-CDMA)) to allow users to access information. Such wireless systems typically operate in limited geographic areas. Expanding such systems to cover larger areas causes network traffic problems due to the large number of users who require service. Furthermore, special services directed to each user increases the price of service to each wireless system user.
Other wireless broadcast systems that are implemented over wider geographic areas offer one-way service (e.g., Digital Audio Broadcasting (DAB), XM satellite radio by XM SATELLITE RADIO INC.), but do not allow information delivery that is tailored to each user""s requests. Such systems therefor limit each user""s ability to select only information that he or she desires. For example, if a user wants to listen to two radio programs, the programs must be broadcast at separate times (either on the same or different channels). As the number of programs and broadcast channels increase, the user""s choices become more restricted. Several systems overcome this problem by storing (e.g., on a disk drive) broadcast programs and therefore allow users to xe2x80x9ctime shiftxe2x80x9d programs.
Some systems send program guides (e.g., television electronic program guide (EPG)) that allow users to tune to receive desired information on a particular channel at a particular time. Such guides, which cover all programs, are content limited and do not contain detailed information. And, one-way service does not allow the user to access information in real- or near real-time. What is desired is a personal information and entertainment system that allows each individual subscriber to tailor received programs in accordance with individual preference, and that can support a large number of users over a wide geographic area. It is also desirable to allow system subscribers to change their individual program requests in real or near real time.
A receiver for a broadcast information system enables the user (system subscriber) to receive preselected programs. In some embodiments the receiver is part of a xe2x80x9cpushxe2x80x9d type broadcast system. In other embodiments the receiver includes a transmitter (transceiver) and is part of a xe2x80x9cpush-pullxe2x80x9d type system. The transceiver allows the user to request, in real or near real time, a program or information he or she chooses. The receiver is configured to work as part of the broadcast system.
The system includes a database of program information. The program information may include features such as music, news features, sports scores, concert ticket information, etc. Programs are broadcast in compressed format using a high speed digital signal. The program signal is divided into frames and each frame contains data for one program available on the system. Large programs may have data in two or more frames. Each program is broadcast at a unique predetermined time or times so that individual programs may be periodically broadcast. If the number of offered programs is large, more than one program signal is used to reduce the time between repeat broadcasts of the frames. For example, program data for programs 1-10 may be broadcast on one channel, and program data for programs 11-20 may be broadcast on another channel. The user""s receiver or transceiver is configured to tune to the appropriate program signal and to download and store the preselected programs. Tuning is accomplished using index data received in a separate signal.
In the xe2x80x9cpushxe2x80x9d embodiments the user preselects one or more program information features the system offers and is given a receiver associated with a unique identifier. The system creates index data for the user by associating the user""s preselected programs with the receiver""s identifier. This association identifies the appropriate program signal channel and the broadcast time for each preselected program. The system then continuously broadcasts the user""s index data in an index signal that also includes index data for many other system users. The index signal is divided into frames, and each system user""s index data is broadcast in a separate frame. The frame begins with the identifier assigned to the user""s receiver, and the receiver monitors the index data signal for its identifier. When the receiver detects its identifier, the receiver downloads and stores the particular user""s index data that follows in the frame. Then, using the index data, the receiver tunes to the correct program signal channel at the correct time and downloads the program data frame(s) associated with the user""s preselected program. The receiver decompresses the program data and outputs the program to the user.
xe2x80x9cPush-pullxe2x80x9d embodiments of the invention allow the user to select one or more frames from the program signal in real- or near real time. The user selects one or more programs by using the transceiver to send a request signal to a wireless (radio) communication system. The user""s request is relayed to the system service center which, in turn, creates and sends index data information directly back to the transceiver. Thus some xe2x80x9cpush-pullxe2x80x9d embodiments may omit the continuously broadcast index data signal. Once the transceiver receives the index data associated with the user""s immediate request, the transceiver tunes to the correct program data channel at the correct time and downloads the user""s requested program.
In some embodiments the system offers global, restricted, and personal programs. Global programs, such as music, news, sports scores, etc., are available to all users at any time. However, the user must have additional authorization to access restricted programs such as special concerts or other high value entertainment. Some embodiments encrypt restricted program data and include the necessary decryption key in the user""s index data when the user pays an additional fee. Personal programs are dedicated to one particular user, and include features such as electronic mail or paging. In embodiments using the transceiver, the user may receive global concert ticket information and an electronic xe2x80x9corder formxe2x80x9d. The user selects a concert and sends to the service center a ticket order along with an electronic payment. The service center responds with a confirmation.
The system is designed to operate over a large geographic area. In many cases the program data signals must be broadcast over different channels in different geographic regions due to the broadcast spectra available in each region. However, this condition is transparent to the user because the index signal broadcast in each region contains the necessary program signal tuning information for the region.